1. Field of the Invention.
The present invention relates to transport devices for bobbins which function as a source of web-like wrapping material and particularly to devices for moving reels of packaging material from storage to a consumption location such as, for example, the unwinding station of a cigarette packaging machine. More specifically, this invention is directed to the exercise of control over a gripping mechanism which is displaceable in three mutually orthoginal directions whereby the gripping mechanism may be aligned with an object to be moved, caused to engage that object and subsequently transport the object to a desired location. Accordingly, the general objects of the present invention are to provide novel and improved apparatus and methods of such character.
2. Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly well suited for use in association with a cigarette package forming machine which employs, as raw material from which the packages are formed, wrapping material in the form of a continuous web. The web-type wrapping material is furnished by the manufacturer thereof on supply reels or bobbins. A plurality of such bobbins will typically be stacked on a pallet. A prior art device for transferring the filled bobbins from a pallet to a consumption station of a cigarette packaging machine may be seen from published German Patent Application DE-A 3,501,692. The apparatus of the referenced application includes a gripping mechanism having jaws which are designed for insertion in the core tube of a bobbin whereupon the bobbin may be engaged, lifted from the pallet and transferred to the consumption station. In order to automate the engagement and transfer operations, the prior art gripping mechanism is displaceable in a plane on a height-adjustable frame by means of linear drives. The frame is provided with bobbin position sensors so that the vertical position of the frame will be adjusted so as to be above a plane defined by the side surface of a bobbin to be transferred. Additional sensors are provided on the gripping mechanism to produce movement thereof in two directions relative to the frame so as to position the gripping mechanism coaxially with the tube of the bobbin to be transferred. Apparatus of the type disclosed in German application 3,501,692 is relatively complex, occupies a substantial amount of factory floor space and requires costly control apparatus.